Heretofore, systems have been employed for moving plants in pots in a greenhouse and for watering the plants as the pots move through a particular area of the greenhouse. An existing system includes having a plurality of hooks on a moving system, with each hook holding a pot. As each hook moves past the particular area of the greenhouse, the hooks abut a switch that activates a system for watering for watering the plants. However, each hook that passes the particular area will activate the switch, whether the plant needs water and even when there is no pot on the hook. A better and easier system for watering plants is desired.